Reliability-based economic model predictive control for generalized flow-based networks including actuators' health-aware capabilities

This paper proposes a reliability-based economic model predictive control (MPC) strategy for the management of generalized flow-based networks, integrating some ideas on network service reliability, dynamic safety stock planning, and degradation of equipment health. The proposed strategy is based on a single-layer economic optimisation problem with dynamic constraints, which includes two enhancements with respect to existing approaches. The first enhancement considers chance-constraint programming to compute an optimal inventory replenishment policy based on a desired risk acceptability level, leading to dynamically allocate safety stocks in flow-based networks to satisfy non-stationary flow demands. The second enhancement computes a smart distribution of the control effort and maximises actuators’ availability by estimating their degradation and reliability. The proposed approach is illustrated with an application of water transport networks using the Barcelona network as the considered case study.Peer ReviewedPostprint (author's final draft

Hemangioma intraóseo de la mandíbula

Introducción: Los hemangiomas son neoplasias benignas de origen vascular que se pueden producir tanto en tejidos blandos como intraóseas. Objetivo: Describir las características clínicas y terapéuticas de un caso raro de paciente con un hemangioma óseo central. Caso clínico: Paciente masculino de 18 años de edad con antecedente de salud, que fue trasladado de urgencia al Hospital General Docente Orlando Pantoja Tamayo de Contramaestre. Santiago de cuba, remitido por su estomatólogo de su área de salud por el sangrado profuso, tras la realización de una sindesmotomía. Fue recibido por el servicio de cirugía maxilofacial, donde se decidió su intervención quirúrgica. Discusión: Los hemangiomas centrales de los maxilares son tumor poco frecuente, pero con alta letalidad por la hemorragia que traen consigo, tal es así que pueden terminar con la vida del paciente. Conclusiones: Estas complicaciones se deben tratar con premura ya que los pacientes pueden fallecer en el acto operatorio. En esta cirugía el paciente tuvo una evolución satisfactoria por lo que pudo incorporarse a su vida social

An Autonomous UAV Architecture for Remote Sensing and Intelligent Decision-making

Recently, the US Department of Transportation’s Federal Aviation Administration and other international organizations have proposed a set of requirements for small unmanned aerial vehicles (UAVs) to operate for nonrecreational purposes. However, existing UAV architectures fulfill only some of the established requirements, and not all in one solution. This article presents an event-driven service-oriented architecture that allows autonomous UAVs to satisfy all these requirements and to detect critical situations, performing real-time decision making

External knowledge acquisition and innovation output: an analysis of the moderating effect of internal knowledge transfer

Numerous studies highlight the advantages of accessing knowledge from outside the firm as a means of enhancing the firm’s innovation efforts. However, access to external knowledge is not without organisational problems, including rejection of external knowledge by firm members or difficulties in applying such knowledge to the firm’s operations. Based on the knowledge management literature, this paper analyses the conditions within the firm that favour external knowledge acquisition, and focuses on internal transfer as a key variable for the successful integration of external knowledge in the innovation process. Our results demonstrate that internal knowledge transfer intensifies the influence of external knowledge acquisition on innovation output. Specifically, achieving an environment within the firm that favours knowledge integration into the innovation process depends to a large extent on the willingness of knowledge users to share and assimilate knowledge, and on th

A distributed predictive control approach for periodic flow-based networks: application to drinking water systems

This paper proposes a distributed model predictive control approach designed to work in a cooperative manner for controlling flow-based networks showing periodic behaviours. Under this distributed approach, local controllers cooperate in order to enhance the performance of the whole flow network avoiding the use of a coordination layer. Alternatively, controllers use both the monolithic model of the network and the given global cost function to optimise the control inputs of the local controllers but taking into account the effect of their decisions over the remainder subsystems conforming the entire network. In this sense, a global (all-to-all) communication strategy is considered. Although the Pareto optimality cannot be reached due to the existence of non-sparse coupling constraints, the asymptotic convergence to a Nash equilibrium is guaranteed. The resultant strategy is tested and its effectiveness is shown when applied to a large-scale complex flow-based network: the Barcelona drinking water supply system.Peer ReviewedPostprint (author's final draft

A service reliability model predictive control with dynamic safety stocks and actuators health monitoring for drinking water networks

This paper presents a model predictive control strategy to assure reliability in drinking water networks given a customer service level and a forecasting demand. The underlying idea concerns a two-layer hierarchical control structure. The upper layer performs a local steady-state optimization to set up an inventory replenishment policy based on dynamic safety stocks for each tank in the network. At the same stage, actuators health is revised to set up their next maximum allowable degradation in order to efficiently distribute overall control effort and guarantee system availability. In the lower layer, a model predictive control algorithm is implemented to compute optimal control set-points to minimize a multiobjective cost function. Simulation results in the Barcelona drinking water network have shown the effectiveness of the dynamic safety stocks allocation and the actuators health monitoring to assure service reliability and optimizing network operational costs.Peer ReviewedPostprint (author’s final draft

Construyendo Perfiles Virtuales Mediante el Procesamiento de Eventos Complejos

A medida que se incrementa el nímero de dispositivos inteligentes, el esfuerzo requerido para adaptarlos a las necesidades de cada usuario también crece. Asimismo, el proceso de adaptación de un dispositivo al contexto de un usuario es todavía un proceso muy manual. A pesar de que en los últimos años han surgido algunas propuestas centradas en obtener la información contextual de los usuarios para crear sus perfiles virtuales, se necesitan soluciones novedosas que permitan crear perfiles más completos, que sean utilizados por los dispositivos inteligentes para adaptarse automáticamente a las necesidades de sus usuarios, redundando en una mayor exactitud de la adaptación. En este artículo se propone la integración del modelo computacional People as a Service (PeaaS) con el procesamiento de eventos complejos (CEP) para la creación en tiempo real de perfiles virtuales complejos desde el propio dispositivo móvil y la compartición de estos como servicios para el resto de sistemas y dispositivos. Además, se evalúa esta integración en un caso de estudio sobre Alzheimer. Los resultados confirman que el uso de la tecnología CEP para la identificación de información contextual compleja es posible.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Invertir en recursos humanos y resultados empresariales: ¿causa o efecto?

This study presents empirical evidence about the «causal» relationship between Organizational Commitment to Employees, OCE (measured by an aggregated index of three indicators: compensation per employee, training expenditures per employee and the proportion of workers without temporary contracts) and two organizational performance measures (Labour Productivity and ROA) using longitudinal research based on a panel of 1,190 Spanish industrial firms and four observation periods (2005-2008). Our results confirm both the traditional view in SHRM, namely, that OCE causes organizational performance, and the reverse causation hypothesis which holds that organizational performance is the cause of OCE.Este trabajo ha obtenido el 1.er Premio Estudios Financieros 2012 en la modalidad de Recursos Humanos. Una cuestión básica pendiente aún de resolución en la literatura de la Gestión Estratégica de los Recursos Humanos es determinar si las empresas invierten en recursos humanos porque les es realmente beneficioso o más bien a la inversa, es decir, cuando tienen beneficios invierten en las personas. Para poder responder a esta cuestión se ha diseñado una investigación de tipo longitudinal en la que se examina la relación causal entre el modelo de Compromiso Organizativo con los Empleados (COE) y los resultados empresariales. A partir de los datos de una muestra de 1.190 empresas industriales españolas durante el periodo 2005-2008, constatamos la existencia de una relación causal recíproca entre el modelo COE y la productividad laboral en la que se observa una retroalimentación positiva entre estas dos variables, es decir, una inversión en recursos humanos genera un aumento de la productividad laboral que, a su vez, genera nuevas inversiones en los empleados. Por otra parte, en el presente estudio se observa también que el COE afecta indirectamente a la rentabilidad económica a través de la productividad laboral. Las implicaciones teóricas y prácticas de estos resultados se dilucidan en este estudio

The optimality of syntactic dependency distances

It is often stated that human languages, as other biological systems, are shaped by cost-cutting pressures but, to what extent? Attempts to quantify the degree of optimality of languages by means of an optimality score have been scarce and focused mostly on English. Here we recast the problem of the optimality of the word order of a sentence as an optimization problem on a spatial network where the vertices are words, arcs indicate syntactic dependencies and the space is defined by the linear order of the words in the sentence. We introduce a new score to quantify the cognitive pressure to reduce the distance between linked words in a sentence. The analysis of sentences from 93 languages representing 19 linguistic families reveals that half of languages are optimized to a 70% or more. The score indicates that distances are not significantly reduced in a few languages and confirms two theoretical predictions, i.e. that longer sentences are more optimized and that distances are more likely to be longer than expected by chance in short sentences. We present a new hierarchical ranking of languages by their degree of optimization. The statistical advantages of the new score call for a reevaluation of the evolution of dependency distance over time in languages as well as the relationship between dependency distance and linguistic competence. Finally, the principles behind the design of the score can be extended to develop more powerful normalizations of topological distances or physical distances in more dimensions

Optimality of syntactic dependency distances

It is often stated that human languages, as other biological systems, are shaped by cost-cutting pressures but, to what extent? Attempts to quantify the degree of optimality of languages by means of an optimality score have been scarce and focused mostly on English. Here we recast the problem of the optimality of the word order of a sentence as an optimization problem on a spatial network where the vertices are words, arcs indicate syntactic dependencies, and the space is defined by the linear order of the words in the sentence. We introduce a score to quantify the cognitive pressure to reduce the distance between linked words in a sentence. The analysis of sentences from 93 languages representing 19 linguistic families reveals that half of languages are optimized to a 70% or more. The score indicates that distances are not significantly reduced in a few languages and confirms two theoretical predictions: that longer sentences are more optimized and that distances are more likely to be longer than expected by chance in short sentences. We present a hierarchical ranking of languages by their degree of optimization. The score has implications for various fields of language research (dependency linguistics, typology, historical linguistics, clinical linguistics, and cognitive science). Finally, the principles behind the design of the score have implications for network science.Peer ReviewedPostprint (published version